Switched Digital Video (SDV) systems operate today with rate capped video content in order to efficiently utilize the quadrature amplitude modulation (QAM)-based distribution systems economically. A typical approach might use a rate cap of 3.75 Mbps for MPEG-2 standard definition (SD) and 15 Mbps for MPEG-2 high definition (HD). These rates support up to 10 SD channels or 2 HD plus 2 SD in a single 6 MHz 256 QAM (38.8 Mbps) pipe.
Adaptive bit rate (ABR) content, in contrast, typically has multiple profiles covering a wide range of bit rates in order to accommodate network bandwidth variations without stalling/rebuffering in order to deliver a smooth viewer experience, albeit potentially with a quality level shift arising from bit rate changes. In any case, transitions from one profile to another are seamless.
Service providers today have existing QAM-based distribution systems and most have now overlaid ABR systems to satisfy their subscriber's demands for IP-based over-the-top (OTT) services such as on-demand streaming content. As a result service providers have to maintain two distinct content distribution networks. Service providers have expressed interest in turning off their legacy distribution network and instead, using only their ABR network to service their subscribers who receive services on OTT devices as well as their subscribers who receive content on set top boxes over the QAM-based distribution systems. However, service providers are also facing significant bandwidth issues as their need to deliver data over cable networks are increasing rapidly, while they still need to deliver significant QAM video to the millions of customers with QAM set tops.